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Message-ID: <3a76730a-d414-c67d-8851-826f86669f2b@huawei.com>
Date:   Wed, 18 Oct 2023 10:22:13 +0800
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Subject: Re: [PATCH v2 1/2] scsi: core: cleanup scsi_dev_queue_ready()
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To:     Bart Van Assche <bvanassche@acm.org>,
        "James E . J . Bottomley" <jejb@linux.ibm.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        <linux-scsi@vger.kernel.org>
CC:     <linux-kernel@vger.kernel.org>, <louhongxiang@huawei.com>
References: <20231016020847.1270258-1-haowenchao2@huawei.com>
 <20231016020847.1270258-2-haowenchao2@huawei.com>
 <b3334a8c-fb48-4b98-8571-8d85cbd4ed1e@acm.org>
From:   Wenchao Hao <haowenchao2@huawei.com>
In-Reply-To: <b3334a8c-fb48-4b98-8571-8d85cbd4ed1e@acm.org>
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On 2023/10/18 5:15, Bart Van Assche wrote:
> On 10/15/23 19:08, Wenchao Hao wrote:
>> +    /*
>> +     * device_blocked is not set at mostly time, so check it first
>> +     * and return token when it is not set.
>> +     */
>> +    if (!atomic_read(&sdev->device_blocked))
>> +        return token;
> 
> This patch looks like an improvement to me. But I don't think that the
> above comment is useful. I propose to move it into the patch
> description.
> 
>> -        /*
>> -         * unblock after device_blocked iterates to zero
>> -         */
>> -        if (atomic_dec_return(&sdev->device_blocked) > 0)
>> -            goto out_dec;
>> -        SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
>> -                   "unblocking device at zero depth\n"));
>> +    /*
>> +     * unblock after device_blocked iterates to zero
>> +     */
>  > +    if (scsi_device_busy(sdev) > 1 ||
>  > +        atomic_dec_return(&sdev->device_blocked) > 0) {
>  > +        sbitmap_put(&sdev->budget_map, token);
>  > +        return -1;
>  >       }
> 
> Please make the above comment match the new code, e.g. by changing it
> into the following: "Only unblock if no other commands are pending and
> if device_blocked has decreased to zero".
> 

OK, would update.

Thanks.

> Thanks,
> 
> Bart.
>